Rep. Mark Sanford (R-S.C.) speaks at his primary night party in Mt. Pleasant, S.C., June 12, 2018. Sanford lost a closely contested primary to Katie Arrington, a state lawmaker who had made Sanford’s frequent criticism of President Donald Trump the centerpiece of her campaign. (Hunter McRae/The New York Times) HUNTER MCRAENYT

Rep. Mark Sanford (R-S.C.) speaks at his primary night party in Mt. Pleasant, S.C., June 12, 2018. Sanford lost a closely contested primary to Katie Arrington, a state lawmaker who had made Sanford’s frequent criticism of President Donald Trump the centerpiece of her campaign. (Hunter McRae/The New York Times) HUNTER MCRAENYT

Trump key, but not the only factor, to Sanford's downfall in 1st District

President Donald Trump may have done what a hike on the Appalachian Trail couldn't — ending, at least for now, U.S. Rep. Mark Sanford's long and turbulent S.C. political career.

Sanford lost his bid for re-election to Congress to a challenger who harped on his public criticism of the president, a factor that turned voters against the incumbent across the district, including in his home county of Beaufort, observers say.

Republican state House Rep. Katie Arrington, who won the 1st District GOP primary Tuesday, said voters were fed up with Sanford's inaction and his lack of support for the president, who endorsed her in a tweet three hours before polls closed.

Arrington also has reminded the Lowcountry district's voters of Sanford's 2009 betrayal. Then S.C. governor, Sanford said he was hiking the Appalachian Trail when he was visiting his mistress in Argentina.

Arrington said Trump's tweet surely "helped prevent a runoff." But on Tuesday, after "11 months of hard work" and knocking on thousands of doors, "the bulk share of people had gone to the polls before the tweet from the president," she said.

Voters are simply "tired of career politicians and the ineffectiveness," she said. "Standing up and saying 'no' does not solve problems."

A 'stunning' upset

Arrington's win was hardly narrow.

Overall, she took about 51 percent of the vote to Sanford's 47 percent, avoiding a runoff.

While her outright win was surprising, her performance in Beaufort County, home to the Sanford family farm, was "stunning," said Citadel political scientist Scott Buchanan.

Arrington won with an 11-percentage point lead in Beaufort County, a sign that voters there turned against Sanford, Buchanan said.

“At the end of the day, this indicates that, in this district, you can’t go around bad-mouthing Trump in public and expect to get away with it," he said.

Republicans in Beaufort County said Trump definitely played a factor in Arrington's win.

"It is the Trump effect," said Joe Iaco, immediate past president of the Bluffton Republican Club.

Sanford's calling for the president to release his tax returns, for example, angered Trump supporters in the district, Iaco said, adding that the president's supporters have become a force in Beaufort County, which picked Trump in the 2016 presidential primary, but not overwhelmingly.

"We believe in the primary process and are confident that she (Arrington) can win in November," Iaco said. "But we do feel a little sorrow in losing the presentation that Sanford provided. He was a fiscal conservative who has represented us well."

Sanford's unraveling

Arrington's win stems from her simple, effective message that contrasted her with Sanford, political observers say.

She would support the president and his agenda — unlike Sanford.

Sanford "wasn't being publicly supportive of the president, and she seized on it," said Greenville GOP consultant Chip Felkel, adding that the message sent Tuesday was there is “an overwhelming importance in voters’ minds of being supportive of the president."

Also, Sanford's Libertarian message did not resonate as much as the populist message Trump has been pushing, Felkel said.

“A populist movement seizes on people being perceived as taking advantage of, and Sanford wasn't saying anything to help them get their piece of the pie," Felkel said.

Sanford also contrasts with the action-oriented approach Trump has taken to governing, others said.

“Part of the Trumpian world is saying things, getting action, being bombastic," the Citadel's Buchanan said.

"That’s not really Mark Sanford. Sanford is prone to philosophical ramblings on the stump. I think that did him in. I don’t think voters have the patience for that anymore.”

Buchanan said it's hard to say whether voters punished Sanford now for cheating on his wife years ago. But the past sin may have helped turn the tide against him.

"Was there a tipping point with Sanford in terms of his personal life? Where people just finally said 'enough'?" Buchanan asked, noting that Arrington and Trump reminded voters of Sanford's tryst with his mistress.

"Mark Sanford and the career politicians cheated on us," she said in one ad, complaining that Sanford makes it a habit to "go on CNN to bash President Trump."

"Bless his heart, but it's time for Mark Sanford to take a hike — for real this time," Arrington said in the ad.

Arrington also said she heard frustration from voters who wanted Sanford to support the district's priorities.

"Mark stands on the principle of being a fiscal conservative, but when you vote 'no' on the funding that we want and not offer up another solution for it, that's a problem. "

He 'made people fight him'

Sanford's political potency also has tapered off in recent years, some say.

Sanford has been known for taking controversial stands, but his messaging has become less effective lately, said his friend and former adviser Scott English, who got a phone call early Wednesday from Sanford, wanting to know what he thought about the race.

In his early years in Congress and as a two-term S.C. governor, Sanford was "the guy who would filibuster appropriations bills, the guy who would stand outside the (S.C. House) chamber with two pigs,” English said.

As governor, Sanford also refused to take Obama-era federal stimulus money for struggling schools and was sued and forced by the state Supreme Court to take the $700 million.

“That was a lonely … battle, but he did it, and he took action, and he made people fight him back.”

Sanford also adeptly controlled the narrative in his 2013 special election bid for Congress.

In the 2013 race, for example, he grabbed headlines by campaigning with a "Vote Sanford" sign hand-painted on a piece of plywood and debated a cardboard photo of Democratic leader Nancy Pelosi, the House Democratic leader.

"In the closing days of that special election, Sanford was running from diner to diner shaking hands with people," English said. “That retail Mark Sanford, that was the last time we saw him.”

In his latest race, Sanford let his opponent control the debate. And at the heart of Arrington’s effectiveness was a call to “stop making excuses for why things can’t get done," English said.

In 2018, Sanford has become a part of a Congress that voters have watched "dither for eight years," giving power all over to Trump through lawmakers' inaction. Voters now are saying, "Thanks for standing for principle, what are you going to do about it?"

“This election reinforced the fact that somewhere along the way Mark Sanford lost his brand," and not the philosophical side, English said.

As for what's next for Sanford, English said the congressman would be successful going the way of former U.S. Sen. Jim DeMint, who left public office to lead the conservative Heritage Foundation, focusing on electing like-minded Republicans to office and pushing conservative policy agendas.

"He still has relevance. I think he still has experience to draw on," English said. "I just think political office is a bad platform for him."